Leo Spiekman

In-service upgrade of an amplified 130-km metro CWDM transmission system using a single LOA with 140-nm bandwidth

We demonstrate a 130-km metro CWDM transmission system using a single LOA with 140-nm bandwidth. An in-service upgrade, for which one of the eight 2.5-Gb/s CWDM channels is replaced with 8/spl times/2.5-Gb/s DWDM channels, results in negligible performance degradation.

Bi-directionally amplified extended reach 40Gb/s CWDM-TDM PON with burst-mode upstream transmission

We demonstrate a 60-km CWDM-TDM PON with 40 Gb/s capacity both down and upstream. The system incorporates technologies such as volume manufacturable transmitters, burst-mode transmission, hybrid SOA-Raman amplifiers, and a cyclic CWDM multiplexer.

Active Devices in Passive Optical Networks

Their name notwithstanding, next-generation passive optical networks will employ many active optical devices. This tutorial addresses the functionality of these devices in the domain of access networking, with a focus on amplifiers for PON extension and components for WDM-PON.

A Symmetric-Rate, Extended-Reach 40 Gb/s CWDM-TDMA PON With Downstream and Upstream SOA-Raman Amplification

We demonstrate an extended reach 60 km coarse wavelength division multiplexing (CWDM)-time division multiple access (TDMA) passive optical network (PON) with 40 Gb/s capacity for both down and upstream directions. The system leverages existing 10 Gb/s TDMA PON technologies and incorporates various subsystems such as volume manufacturable optical transmitters, a prototype 10 Gb/s burst-mode receiver, hybrid semiconductor optical amplifier-Raman amplifiers, and a cyclic CWDM multiplexer. We confirm that this 32-user system has sufficient power margin to accommodate 128 users.

Semiconductor Optical Amplifiers for FTTx

Access networking is a hot topic. After Japan and Korea, demand is now picking up also in Europe and the US. After cherry-picking the easy installs, operators find that they could use a power boost in their passive optical networks to reach further out neighbourhoods from their present set of PON central offices. Hence the push for introducing optical amplification in access. As always, the main aim is cost reduction. Fewer COs means lower opex, while amplification before the PON splitter may mean higher split ratios, which in turn means that the same central office equipment can serve more end customers. Given the wavelength plan of a typical PON, the choice of optical amplifiers is limited to SOAs or Raman-assisted SOAs, depending on whether gain-flattened operation in a CWDM-PON is desired. Possible locations of the amplifier are as a booster/preamp at the OLT, or as a line amplifier near the passive splitter. These set different output power / noise figure requirements, where the in-line configuration allows for longer distances between the CO and the end customer, and/or higher split ratios. Operating regimes to be distinguished are NF-limited, gain limited, and power limited. Access networking is a hot topic. After Japan and Korea, demand is now picking up also in Europe and the US. After cherry-picking the easy installs, operators find that they could use a power boost in their passive optical networks to reach further out neighbourhoods from their present set of PON central offices. Hence the push for introducing optical amplification in access. As always, the main aim is cost reduction. Fewer COs means lower opex, while amplification before the PON splitter may mean higher split ratios, which in turn means that the same central office equipment can serve more end customers. Given the wavelength plan of a typical PON, the choice of optical amplifiers is limited to SOAs or Raman-assisted SOAs, depending on whether gain-flattened operation in a CWDM-PON is desired. Possible locations of the amplifier are as a booster/preamp at the OLT, or as a line amplifier near the passive splitter. These set different output power / noise figure requirements, where the in-line configuration allows for longer distances between the CO and the end customer, and/or higher split ratios. Operating regimes to be distinguished are NF-limited, gain limited, and power limited.

Dynamic add/drop of 8-of-16 10 Gb/s channels in 4/spl times/40 km semiconductor-optical-amplifier-based WDM system

We demonstrate the benefits of near-linear SOA-amplified 4/spl times/40 km WDM transmission system. Eight out of sixteen 10 Gb/s channels are added or dropped (with only a 0.7 bB penalty in the remaining channels) over a wide range of time scales.

Regeneration using an SOA-MZI in a 100-pass 10,000-km Recirculating Fiber Loop

We demonstrate all-optical regeneration in an SOA-MZI on a 10-Gb/s picosecond pulse train over 10,000 km in a 100-km recirculating loop. The bit-error rate after 100 loop-passes shows a 0.5-dB penalty.

Semiconductor optical amplifiers in access networks

We review the uses of semiconductor optical amplifiers (SOAs) in passive optical networks (PONs). SOAs can be used to extend the reach and split ratio of the network. Reflective SOAs can be used as wavelength-agnostic modulators in Wavelength Division Multiplexed PON.

Semiconductor optical amplifiers for all transmission wavelength bands

Summary form only given. An overview is presented of the progress in design and characteristics of semiconductor optical amplifiers (SOA) for 1310, 1400 and 1550 nm operation in fiber optical transmission systems. The technology and performance of SOAs will be discussed with respect to optical gain, noise figure, saturation output power and polarization (in-) dependent behavior. The use of both strained quantum wells and bulk tensile material will be discussed in view of obtaining polarization independent behavior. Gain clamping in SOAs has been shown to improve the linearity performance especially for analogue signal transmission. The SOA technology has been demonstrated for optical pre-amplification, in-line application and optical booster applications. DWDM experiments using SOAs in up to 20 Gbit/s systems in short- and medium-distance transmission will be highlighted. Also, SOAs have been used in optical demultiplexing from 40 Gbit/s down to 10 Gbit/s RZ signals using its phase properties and in integrated photonic devices like multiwavelength lasers.

Spectral coherent-state quantum cryptography

A novel implementation of quantum-noise optical cryptography is proposed, which is based on a simplified architecture that allows long-haul, high-speed transmission in a fiber optical network. By using a single multiport encoder/decoder and 16 phase shifters, this new approach can provide the same confidentiality as other implementations of Yuens encryption protocol, which use a larger number of phase or polarization coherent states. Data confidentiality and error probability for authorized and unauthorized receivers are carefully analyzed.